I'll agree, it's very human and natural for people to deliberately misunderstand things so they can work themselves into a rage over things. It's intellectually dishonest, particularly in this case, and so I give it no shrift.

If all you have to make your case is rhetorical tricks (like "look! somewhere in this man's million plus words he talked about Africans being slaves! Slavery is therefore a specific kind of racist in all conversations") then I work from the premise that there isn't much of a case to be made.